Updated Subtype

I updated the SubType TrueType. I see some research saying that Type1 fonts are seeing declining support.

I didn't see any change in functionality, but figured it would be good to make the change regardless.

pypdf/_writer.py

@@ -839,7 +839,7 @@ def _update_field_annotation(
             font_dict = dr["/Font"]
             font_entry = DictionaryObject({
                 NameObject("/Type"): NameObject("/Font"),
-                NameObject("/Subtype"): NameObject("/Type1"),
+                NameObject("/Subtype"): NameObject("/TrueType"),
                 NameObject("/BaseFont"): NameObject("/Helvetica"),
                 NameObject("/Encoding"): NameObject("/WinAnsiEncoding")
             })